Vanadium Compounds with Antidiabetic Potential.

Over the last four decades, vanadium compounds have been extensively studied as potential antidiabetic drugs. With the present review, we aim at presenting a general overview of the most promising compounds and the main results obtained with in vivo studies, reported from 1899-2023. The chemistry of vanadium is explored, discussing the importance of the structure and biochemistry of vanadate and the impact of its similarity with phosphate on the antidiabetic effect. The spectroscopic characterization of vanadium compounds is discussed, particularly magnetic resonance methodologies, emphasizing its relevance for understanding species activity, speciation, and interaction with biological membranes. Finally, the most relevant studies regarding the use of vanadium compounds to treat diabetes are summarized, considering both animal models and human clinical trials. An overview of the main hypotheses explaining the biological activity of these compounds is presented, particularly the most accepted pathway involving vanadium interaction with phosphatase and kinase enzymes involved in the insulin signaling cascade. From our point of view, the major discoveries regarding the pharmacological action of this family of compounds are not yet fully understood. Thus, we still believe that vanadium presents the potential to help in metabolic control and the clinical management of diabetes, either as an insulin-like drug or as an insulin adjuvant. We look forward to the next forty years of research in this field, aiming to discover a vanadium compound with the desired therapeutic properties.

Toxicity studies of sodium metavanadate and vanadyl sulfate administered in drinking water to Sprague Dawley (Hsd:Sprague Dawley SD) rats and B6C3F1/N mice.

Oral human exposure to vanadium may occur due to its presence in food and drinking water and its use in dietary supplements. The most prevalent oxidation states of vanadium in food and drinking water have been characterized as tetravalent and pentavalent. Vanadyl sulfate and sodium metavanadate were selected as representative tetravalent (V4+) and pentavalent (V5+) test articles for these studies, respectively. To assess the potential for oral toxicity of vanadium compounds with differing oxidation states under similar test conditions, the 3-month National Toxicology Program (NTP) toxicity studies of sodium metavanadate and vanadyl sulfate were conducted in male and female Sprague Dawley (Hsd:Sprague Dawley SD) rats (including perinatal exposure) and in B6C3F1/N mice. Drinking water concentrations for sodium metavanadate (0, 31.3, 62.5, 125, 250, and 500 mg/L) and vanadyl sulfate (0, 21.0, 41.9, 83.8, 168, and 335 mg/L) were selected on the basis of previously published 14-day drinking water studies conducted as part of the NTP vanadium research program. (Abstract Abridged).

Phytotoxicity of VO2 nanoparticles with different sizes to pea seedlings.

Vanadium dioxide nanoparticles (VO2 NPs) have been massively produced due to their excellent metal-insulator transition characteristics for various applications. Pilot studies indicated the toxicity of VO2 NPs to bacteria and mammalian cells, but the environmental hazards of VO2 NPs to plants have been unrevealed to date. In this study, we reported the inhibitive effects of VO2 NPs to the growth and photosynthesis of pea seedlings. Laboratory synthesized monoclinic VO2 NPs (N-VO2), commercial nanosized VO2 NPs (S-VO2), and commercial microsized VO2 particles (M-VO2) were carefully characterized for environmental toxicity evaluations. VO2 particles were supplemented to culture medium for seed germination and seedling growth. All three VO2 samples did not affect the germination rates of pee seeds, while serious growth inhibition of pea seedlings was observed at 10 mg/L for S-VO2 and N-VO2, and 100 mg/L for M-VO2. VO2 particles had no impact on the chlorophyll contents, but the photosynthesis of leaf was significantly decreased following the consequence of N-VO2 > S-VO2 > M-VO2. The inhibition of photosynthesis was attributed to the damage of acceptor side of photosystem II by VO2 particles at high concentrations. Abundant bioaccumulations of vanadium in roots aroused oxidative damage and changed the root structure. Our results collectively indicated that the phytotoxicity of VO2 NPs was related to the concentration, size and crystalline degree.

Influence of calcium channel modulators on the production of serotonin, gentisic acid, and a few other biosynthetically related phenolic metabolites in seedling leaves of salt tolerant rice variety Nonabokra.

Rice, a most salt-sensitive cereal plant, adopts diverse pathways to withstand sodium chloride-induced salinity-related adversities. During the present study, attempt was made to understand the role of calcium on metabolite profile of the leaves of salt tolerant rice seedlings of variety of Nonabokra under sodium chloride induced salinity, by Gas Chromatography-Mass Spectrometry-based metabolomics approach. Calcium availability in the seedlings was reduced or enhanced applying inhibitors (vanadyl sulfate, lanthanum chloride, and verapamil) or promoters of calcium influx (calcimycin also known as calcium ionophore A23187) in the sodium chloride (100 mM) supplemented growth medium. Growth medium of ten-day-old seedlings was replaced by sodium chloride supplemented hydroponic solution with promotor or inhibitors of calcium channel. Fifteen days old seedlings were harvested. It was observed that depletion of calcium availability increased the level of serotonin and gentisic acid whereas increased calcium level decreased these metabolites. It was concluded from the results that production of the signaling molecules serotonin and gentisic acids was elevated in calcium-deficient seedlings under salt stress the condition that was considered as control during the experiment. The two signaling molecules probably help this tolerant rice variety Nonabokra to withstand the salt-induced adversities.

First-principles insights into the adsorption and interaction mechanism of selenium on selective catalytic reduction catalyst.

Selenium (Se) species can deposit in selective catalytic reduction (SCR) system during the denitrification process, which is harmful to the catalyst. To improve the Se-poisoning resistance of SCR catalysts, the influence mechanism of Se species on vanadium-titanium-based catalysts should be elucidated from an atomic scale. In this paper, theoretical calculations were conducted to reveal the adsorption and interaction mechanism of Se species on V2O5-WO3(MoO3)/TiO2 surface based on the first-principles. The impact of Se species on the electronic structure of the catalyst was investigated from electron transfer, bond formation, and VO site activity. The results show that the adsorption of elementary Se (Se0) belongs to chemisorption, while SeO2 can undergo both physisorption and chemisorption. For the chemisorption of Se species, obvious charge transfer with the catalyst is observed and Se-O bond is formed, which enhances the oxidation activity of the catalyst, triggers the reaction of Se0 and SeO2 with the catalyst components to generate SeVOx and SeW(Mo)Ox. The active sites are thereby damaged and the SCR performance is reduced. The above conclusions are mutually confirmed with the previous experimental research. By studying the correlation with the adsorption energies of Se species, descriptors manifesting the Se species adsorption were initially investigated to unveil the relationship between the electronic structure and the adsorption energy. Finally, the influence of temperature on Se adsorption was investigated. The adsorption can only proceed spontaneously below 500 K and is inhibited at high temperatures.

Energy-efficient Mott activation neuron for full-hardware implementation of neural networks.

To circumvent the von Neumann bottleneck, substantial progress has been made towards in-memory computing with synaptic devices. However, compact nanodevices implementing non-linear activation functions are required for efficient full-hardware implementation of deep neural networks. Here, we present an energy-efficient and compact Mott activation neuron based on vanadium dioxide and its successful integration with a conductive bridge random access memory (CBRAM) crossbar array in hardware. The Mott activation neuron implements the rectified linear unit function in the analogue domain. The neuron devices consume substantially less energy and occupy two orders of magnitude smaller area than those of analogue complementary metal-oxide semiconductor implementations. The LeNet-5 network with Mott activation neurons achieves 98.38% accuracy on the MNIST dataset, close to the ideal software accuracy. We perform large-scale image edge detection using the Mott activation neurons integrated with a CBRAM crossbar array. Our findings provide a solution towards large-scale, highly parallel and energy-efficient in-memory computing systems for neural networks.

Internal dose of vanadium in rats following repeated exposure to vanadyl sulfate and sodium orthovanadate via drinking water.

Vanadium is a ubiquitous environmental contaminant that exists in multiple oxidation states. Humans are exposed to vanadyl (V4+) and vanadate (V5+) from dietary supplements, food, and drinking water and hence there is a concern for adverse human health. The current investigation is aimed at identifying vanadium oxidation states in vitro and in vivo and internal concentrations following exposure of rats to vanadyl sulfate (V4+) or sodium metavanadate (V5+) via drinking water for 14 d. Investigations in simulated gastric and intestinal fluids showed that V4+ was stable in gastric fluid while V5+ was stable in intestinal fluid. Analysis of rodent plasma showed that the only vanadium present was V4+, regardless of the exposed compound suggesting conversion of V5+ to V4+ in vivo and/or instability of V5+ species in biological matrices. Plasma, blood, and liver concentrations of total vanadium, after normalizing for vanadium dose consumed, were higher in male and female rats following exposure to V5+ than to V4+. Following exposure to either V4+ or V5+, the total vanadium concentration in plasma was 2- to 3-fold higher than in blood suggesting plasma as a better matrix than blood for measuring vanadium in future work. Liver to blood ratios were 4-7 demonstrating significant tissue retention following exposure to both compounds. In conclusion, these data point to potential differences in absorption and disposition properties of V4+ and V5+ salts and may explain the higher sensitivity in rats following drinking water exposure to V5+ than V4+ and highlights the importance of internal dose determination in toxicology studies.

Ratiometric Dual Signal-Enhancing-Based Electrochemical Biosensor for Ultrasensitive Kanamycin Detection.

Based on the signal amplification elements of planar VS2/AuNPs nanocomposites and CoFe2O4 nanozyme, we herein developed an electrochemical biosensor for sensitive kanamycin (Kana) quantification. A ratiometric sensing platform was presented by incorporating VS2/AuNPs nanocomposites as a support material with excellent conductivity and high specific surface area, as well as hairpin DNA (hDNA) with complementary hybridization of biotinylated Kana-aptamer. In addition, streptavidin-functionalized CoFe2O4 nanozyme with superior peroxidase-like catalytic activity were immobilized onto the aptasensor, hence the peroxidase-like catalytic reaction could yield amplified electrochemical signals. With the presence of Kana, the aptamer-biorecognition resulted in a quantitative decrease of nanozyme accumulation and an increase of methylene blue response. Under optimal conditions, the electrochemical signal ratio of the aptasensor revealed a linear relation along with the logarithmic concentration of Kana from 1 pM to 1 µM, with the limit of detection reaching to 0.5 pM. Moreover, this aptasensor exhibited excellent precision, as well as high repeatability, hence possessing potentials in real samples and for diverse targets detection by easy replacement of the matched aptamer.

VS2 and its doped composition: Catalytic depolymerization of alkali lignin for increased bio-oil production.

VS2 spheres and VS2 sheets with doped compositions (Mo, Ag and graphite) were successfully prepared by one-step hydrothermal method and characterized by different techniques including X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N2 adsorption isotherms. Catalysts were applied for the depolymerization of alkali lignin. VS2 spheres exhibited lower yield of degraded lignin and bio-oil than those with VS2 sheets and VS2 flowers heated to 250 °C and held for 1.5 h with 2.0 MPa H2. The catalytic depolymerization performance was markedly affected by the dopant in the VS2 sheets, with the highest degraded lignin yield of 81.22%, achieved over 5 wt% Ag-VS2 at 290 °C under 2.0 MPa H2 for 1.5 h, yielding 61.23% bio-oil. The VS2-based catalysts show excellent selectivity in the interruption of the lignin structure and target production of bio-oil. The bio-oil showed that the relevant contents of a phenolic-type compound changes significantly according to the dopant in the VS2 catalyst.

Vanadium compounds induced damage of human umbilical vein endothelial cells and the protective effect of berberine.

This study was conducted to investigate the damage caused by vanadium compounds and to explore the protective effects of berberine (BBR) in human umbilical vein endothelial cells (HUVECs). BBR is a biologically active small molecule found in Coptis rhizome, a remedy used in traditional Chinese medicine to treat diabetes. BBR has also been shown to lower blood glucose in diabetic patients. MTT assay was performed to observe the influence of bis(acetylacetonato)-oxidovanadium [VO(acac)2] or sodium metavanadate (NaVO3) and BBR on viability of HUVECs. The monolayer permeability of the HUVECs was assessed by measuring the transendothelial electrical resistance (TER). The endothelial nitric oxide synthase (eNOS) activity was detected by ELISA. Flow cytometry was performed to detect the generation of reactive oxygen species (ROS). The results showed that the viability of HUVECs was decreased by treatment with vanadium compounds 50-400 µM in a concentration-dependent manner, while 0.01-1 µM BBR effectively protected HUVECs from the inhibitory effects of vanadium compounds on cell viability. Also 100 and 200 µM VO(acac)2 induced high permeability and decreased eNOS activity in HUVECs. While 0.01-1 µM BBR showed no improvement in the permeability, and failed to reverse the VO(acac)2-induced changes of eNOS activity, but BBR treatment increased the eNOS activity in control cells. The addition of 200 µM VO(acac)2 significantly induced ROS generation in HUVECs, while 0.01 or 0.1 µM BBR reversed the change of ROS. In summary, BBR has protective effects in HUVECs damage induced by vanadium compounds, which is not mediated by eNOS, but related to reduced intracellular ROS.

pH-activated heat shock protein inhibition and radical generation enhanced NIR luminescence imaging-guided photothermal tumour ablation.

Photothermal therapy had great potential in being a new approach of tumour ablation due to their high selectivity and low side effect. However, the shallow penetration depth of near-infrared (NIR) irradiation resulted in the limited curative effect. Herein, a novel nanomedicine was developed based on the indocyanine green-loaded vanadium oxide nanocomposites (VO2-ICG) for pH-activated NIR luminescence imaging-guided enhanced photothermal tumour ablation. In acidic tumour microenvironment, the VO2 NPs were decomposed and released VO2+, which could not only inhibit the function of 60 kDa heat shock protein (HSP60), but also generate hydroxyl radical (OH) by catalysing intratumoral H2O2. Furthermore, the ICG was also released in the decomposition process of VO2 NPs, allowing the pH-activated NIR luminescence imaging and photothermal therapy. The inhibition of HSP60 down-regulated the heat tolerance of cells and the generation of OH up-regulated the intracellular oxidative stress, which enhanced the photothermal therapeutic efficiency. Our work demonstrated a promised method to enhance photothermal therapeutic effect, highlighting the importance of HSP inhibition and OH generation in promoting cell apoptosis under mild hyperthermia.

Developing Vanadium as an Antidiabetic or Anticancer Drug: A Clinical and Historical Perspective.

Vanadium has been known for centuries to have beneficial effects on health and has the potential to be used as an alternative to other diabetic and anticancer medicines. The beneficial effects of vanadium salts or organic compounds have been explored in vitro, ex vivo, and in vivo in animal and human studies. A consensus among researchers is that increased bioavailability of these compounds could markedly increase the efficacy of this class of compounds. In addition, because many commercially available vanadium derivatives are being used by body builders to enhance performance, more understanding of their mode of action is desirable. Future studies of various vanadium compounds need to evaluate their biodistribution, biotransformation, and the effects of food and formulation on the bioavailability of the compounds. To date, most studies in humans have employed vanadium salts, mainly vanadyl sulfate, and dose-limiting side effects were reported at therapeutic doses. One organic vanadium compound, bis(ethylmaltolato)oxovanadium(IV), had improved efficacy compared to the vanadyl sulfate and was selected for Phase 1 and 2 clinical trials. Future studies should be conducted as randomized, placebo controlled trials lasting several months, with monitoring of both fasting blood glucose and hemoglobin A1c. Now, the most promising potential uses of vanadium compounds are as nutritional supplements to control glucose levels and perhaps, as an anticancer agent potentiated by immunotherapy.

Genotoxic And Cytotoxic Effects Of Oral Vanadyl Sulphate.

BACKGROUND: Vanadyl sulphate is available as herbal medicine against diabetes mellitus and body building supplement, over the counter worldwide. The available data on its safety is controversial and inadequate. The objective of this study was to analyse its safety in usual therapeutic dose range. METHODS: It was an experimental study carried out at the Department of Biochemistry & Molecular Biology, Army Medical College, National University of Medical Sciences (NUMS), Rawalpindi, Pakistan, from Jun 2014 to Oct 2018. The study was carried out on 105 Sprague Dawley rats for duration of 24 weeks. The animals were randomly distributed in three groups of 35 each. The group I rats were marked as control while rats of group II & III were administered vanadyl sulphate 0.06mg/day and 0.3mg/day respectively. Alanine amino transferase (ALT) and Malondialdehyde (MDA) were measured in serum while comet assay was performed on WBCs. RESULTS: The plasma levels of ALT and MDA were significantly raised in group II and III subjects. Single cell gel electrophoresis (SCGE) / comet assay showed minimal "tail moment" in control group and increased tail moment in group II and III in a dose dependent manner which indicates dsDNA breaks. CONCLUSIONS: It was observed that vanadyl sulphate causes hepatocellular toxicity, oxidative stress and damage to the DNA in usual therapeutic/ supplemental doses. Due to hazardous effects, its use in humans as alternate medicine may be reviewed.

Green synthesis of ultra-small VOx nanodots for acidic-activated HSP60 inhibition and therapeutic enhancement.

Using metal oxide semiconductor nanomaterials for synergistic cancer treatment has recently attracted the attention of numerous researchers. Herein, oxygen-defective vanadium oxide nanodots (VOx NDs) with ultra-small size and great dispersibility were synthesized via a novel user-friendly method, and then doxorubicin was loaded onto the VOx NDs surfaces. The VOx NDs had great photothermal conversion efficiency and stability. Doxorubicin-loaded VOx NDs can simultaneously serve as therapeutic agent and tumor microenvironment-activable HSP60 inhibitor, resulting in improved efficacy of photothermal therapy and released active doxorubicin for chemotherapy. Finally, we show that synergistic treatment achieved significant therapeutic effects in mice. These results provided a promising strategy for developing novel methods of synthesizing metal oxide semiconductors for enhanced synergistic cancer treatment.

Evaluation of lipid peroxidation and the level of some elements in rat erythrocytes during separate and combined vanadium and magnesium administration.

The impact of vanadium (V) and magnesium (Mg) as sodium metavanadate (SMV, 0.125 mg V/ml) and magnesium sulfate (MS, 0.06 mg Mg/ml) on lipid peroxidation (LPO) and selected elements in the rat erythrocytes (RBCs) was investigated. Relationships between some indices determined in RBC were also studied. SMV alone (Group II) elevated the malondialdehyde level (MDARBC) (by 95% and 60%), compared with the control (Group I) and MS-supplemented rats (Group III), respectively, reduced the concentration of CuRBC (by 23.5%), in comparison with Group I, but did not change the levels of NaRBC, KRBC, and CaRBC, whereas MS alone (Group III) only reduced the CuRBC concentration (by 22%), compared with Group I. The SMV + MS combination (Group IV) reduced and elevated the CuRBC (by 24%) and CaRBC (by 111%) concentrations, respectively, in comparison with Groups I and III, and these changes were induced by the V-Mg antagonistic and synergistic interaction, respectively. The combined SMV + MS effect also enhanced the MDARBC level, compared with Groups I (by 79%) and III (by 47%) and slightly limited its concentration, compared with Group II, which, in turn, resulted from the distinct trend toward the V-Mg antagonistic interaction. We can conclude that V (as SMV) is able to stimulate LPO in rat RBCs and that V-Mg interactive effects are involved in changes in CuRBC, CaRBC, and MDARBC. Further studies are needed to elucidate the exact mechanisms of the V-Mg antagonistic/synergistic interactions and to provide insight into the biochemical mechanisms of changes in rats suffering from anemia [1], characterized by a disrupted antioxidant barrier in RBCs [2] and an intensified free radical process in these cells.

Respirable Uranyl-Vanadate-Containing Particulate Matter Derived From a Legacy Uranium Mine Site Exhibits Potentiated Cardiopulmonary Toxicity.

Exposure to windblown particulate matter (PM) arising from legacy uranium (U) mine sites in the Navajo Nation may pose a human health hazard due to their potentially high metal content, including U and vanadium (V). To assess the toxic impact of PM derived from Claim 28 (a priority U mine) compared with background PM, and consider the putative role of metal species U and V. Two representative sediment samples from Navajo Nation sites (Background PM and Claim 28 PM) were obtained, characterized in terms of chemistry and morphology, and fractioned to the respirable (≤ 10 µm) fraction. Mice were dosed with either PM sample, uranyl acetate, or vanadyl sulfate via aspiration (100 µg), with assessments of pulmonary and vascular toxicity 24 h later. Particulate matter samples were also examined for in vitro effects on cytotoxicity, oxidative stress, phagocytosis, and inflammasome induction. Claim 28 PM10 was highly enriched with U and V and exhibited a unique nanoparticle ultrastructure compared with background PM10. Claim 28 PM10 exhibited enhanced pulmonary and vascular toxicity relative to background PM10. Both U and V exhibited complementary pulmonary inflammatory potential, with U driving a classical inflammatory cytokine profile (elevated interleukin [IL]-1ß, tumor necrosis factor-α, and keratinocyte chemoattractant/human growth-regulated oncogene) while V preferentially induced a different cytokine pattern (elevated IL-5, IL-6, and IL-10). Claim 28 PM10 was more potent than background PM10 in terms of in vitro cytotoxicity, impairment of phagocytosis, and oxidative stress responses. Resuspended PM10 derived from U mine waste exhibit greater cardiopulmonary toxicity than background dusts. Rigorous exposure assessment is needed to gauge the regional health risks imparted by these unremediated sites.

Health Benefits of Vanadium and Its Potential as an Anticancer Agent.

Vanadium compounds have been known to have beneficial therapeutic properties since the turn of the century, but it was not until 1965 when it was discovered that those effects could be extended to treating cancer. Some vanadium compounds can combat common markers of cancer, which include metabolic processes that are important to initiating and developing the phenotypes of cancer. It is appropriate to consider vanadium as a treatment option due to the similarities in some of the metabolic pathways utilized by both diabetes and cancer and therefore is among the few drugs that are effective against more than one disease. The development of vanadium compounds as protein phosphatase inhibitors for the treatment of diabetes may be useful for potential applications as an anticancer agent. Furthermore, the ability of vanadium to redox cycle is also important for biological properties and is involved in the pathways of reactive oxygen species. Early agents including vanadocene and peroxovanadium compounds have been investigated in detail, and the results can be used to gain a better understanding of how some vanadium compounds are modifying the metabolic pathways potentially developing cancer. Considering the importance of coordination chemistry to biological responses, it is likely that proper consideration of compound formulation will improve the efficacy of the drug. Future development of vanadium-based drugs should include consideration of drug formulation at earlier stages of drug development.

Influence of Feeding Inorganic Vanadium on Growth Performance, Endocrine Variables and Biomarkers of Bone Health in Crossbred Calves.

The nutritional essentialities of transition element vanadium (V) as micro-nutrient in farm animals have not yet been established, though in rat model, vanadium as vanadate has been reported to exert insulin-mimetic effect and shown to be needed for proper development of bones. The objective of this study was to determine the effect of V supplementation on growth performance, plasma hormones and bone health status in calves. Twenty-four crossbred calves (body weight 72.83 ± 2.5 kg; age 3-9 months) were blocked in four groups and randomly assigned to four treatment groups (n = 6) on body weight and age basis. Experimental animals were kept on similar feeding regimen except that different groups were supplemented with either 0, 3, 6 or 9 ppm inorganic V/kg DM. Effect of supplementation during 150-day experimental period was observed on feed intake, body weight gain, feed efficiency, body measures, endocrine variables, plasma glucose and biomarkers of bone health status. Supplementation of V did not change average daily gain (ADG), dry matter intake (DMI), feed efficiency and body measures during the experimental period. During the post-V supplementation period plasma insulin-like growth factor-1 (IGF-1), triiodothyronine (T3) and thyroxin (T4) concentrations were increased and observed highest in 9 mg V/kg DM fed calves; however, levels of insulin, glucose, parathyroid hormone (PTH) and calcitonin hormones remained similar among calves fed on basal or V-supplemented diets. Bone alkaline phosphatase (Bone-ALP) concentration was increased (P < 0.05); however, plasma protein tyrosine phosphatase (PTP) level decreased (P < 0.05) in 6 and 9 mg V/kg DM supplemented groups. Plasma hydroxyproline (Hyp) and tartrate-resistant acid phosphatase (TRAP) concentration were unchanged by V supplementation. Blood V concentration showed positive correlation with supplemental V levels. These results suggest that V may play a role in modulation of the action of certain endocrine variables and biomarkers of bone health status in growing crossbred calves.

Vanadium(V) complexes with hydrazides and their spectroscopic and biological properties.

The present study explores the synthesis and inhibitory potential of vanadium(V) complexes of hydrazides (1c-12c) against oxidative enzymes including xanthine oxidase and lipoxygenase (LOX). In addition, non-enzymatic radical scavenging activities of these complexes were also determined. On the basis of spectral, elemental and physical data, synthesized vanadium(V) complexes are tentatively assigned to have an octahedral geometry with two hydrazide ligands and two oxo groups forming a negatively charged sphere complex with ammonium as counter ion. This is further verified by the conductivity studies of the complexes. Results show that hydrazide ligands (1-12) and their respective vanadium(V) complexes (1c-12c) posses scavenging and inhibition potential against DPPH and LOX, respectively. However, contrary to that uncoordinated ligands showed no activity against nitric oxide, superoxide and xanthine oxidase whereas their complexes showed varying degree of activity. These studies indicate that geometry of complex, nature and position of substituent groups play a vital role in scavenging and inhibition potential of these compounds.

Degradable Vanadium Disulfide Nanostructures with Unique Optical and Magnetic Functions for Cancer Theranostics.

Multifunctional biodegradable inorganic theranostic nano-agents are of great interest to the field of nanomedicine. Upon lipid modification, VS2 nanosheets could be converted into ultra-small VS2 nanodots encapsulated inside polyethylene glycol (PEG) modified lipid micelles. Owing to paramagnetism, high near-infrared (NIR) absorbance, and chelator-free 99m Tc4+ labeling of VS2 , such VS2 @lipid-PEG nanoparticles could be used for T1-weighted magnetic resonance (MR), photoacoustic (PA),and single photon emission computed tomography (SPECT) tri-modal imaging guided photothermal ablation of tumors. Importantly, along with the gradual degradation of VS2 , our VS2 @lipid-PEG nanoparticles exhibit effective body excretion without appreciable toxicity. The unique advantages of VS2 nanostructures with highly integrated functionalities and biodegradable behaviors mean they are promising for applications in cancer theranostics.